In
Human papillomavirus (HPV), two late proteins are involved in
capsid formation: a major (L1) and a minor (L2) protein, in the approximate proportion 95:5%. L1 forms a
pentameric assembly unit of the
viral shell in a manner that closely resembles VP1 from
polyomaviruses. Intermolecular disulphide bonding holds the L1
capsid proteins together.[3] L1 capsid proteins can bind via its
nuclear localisation signal (NLS) to
karyopherins Kapbeta(2) and Kapbeta(3) and inhibit the Kapbeta(2) and Kapbeta(3) nuclear import pathways during the productive phase of the
viral life cycle.[4] Surface loops on L1
pentamers contain sites of
sequence variation between HPV types. L2 minor capsid
proteins enter the nucleus twice during infection: in the initial phase after
virion disassembly, and in the productive phase when it assembles into replicated virions along with L1 major capsid proteins. L2 proteins contain two nuclear localisation signals (NLSs), one at the
N-terminal (nNLS) and the other at the
C-terminal (cNLS). L2 uses its NLSs to
interact with a network of
karyopherins in order to enter the nucleus via several import pathways. L2 from HPV types 11 and 16 was shown to
interact with karyopherins Kapbeta(2) and Kapbeta(3).[5][6] L2 capsid proteins can also interact with
viraldsDNA, facilitating its release from the
endocytic compartment after viral uncoating.
^Nelson LM, Rose RC, Moroianu J (February 2003). "The L1 major capsid protein of human papillomavirus type 11 interacts with Kap beta2 and Kap beta3 nuclear import receptors". Virology. 306 (1): 162–9.
doi:
10.1016/S0042-6822(02)00025-9.
PMID12620808.
In
Human papillomavirus (HPV), two late proteins are involved in
capsid formation: a major (L1) and a minor (L2) protein, in the approximate proportion 95:5%. L1 forms a
pentameric assembly unit of the
viral shell in a manner that closely resembles VP1 from
polyomaviruses. Intermolecular disulphide bonding holds the L1
capsid proteins together.[3] L1 capsid proteins can bind via its
nuclear localisation signal (NLS) to
karyopherins Kapbeta(2) and Kapbeta(3) and inhibit the Kapbeta(2) and Kapbeta(3) nuclear import pathways during the productive phase of the
viral life cycle.[4] Surface loops on L1
pentamers contain sites of
sequence variation between HPV types. L2 minor capsid
proteins enter the nucleus twice during infection: in the initial phase after
virion disassembly, and in the productive phase when it assembles into replicated virions along with L1 major capsid proteins. L2 proteins contain two nuclear localisation signals (NLSs), one at the
N-terminal (nNLS) and the other at the
C-terminal (cNLS). L2 uses its NLSs to
interact with a network of
karyopherins in order to enter the nucleus via several import pathways. L2 from HPV types 11 and 16 was shown to
interact with karyopherins Kapbeta(2) and Kapbeta(3).[5][6] L2 capsid proteins can also interact with
viraldsDNA, facilitating its release from the
endocytic compartment after viral uncoating.
^Nelson LM, Rose RC, Moroianu J (February 2003). "The L1 major capsid protein of human papillomavirus type 11 interacts with Kap beta2 and Kap beta3 nuclear import receptors". Virology. 306 (1): 162–9.
doi:
10.1016/S0042-6822(02)00025-9.
PMID12620808.